Microprocessor Controller for DOAS
20
d
ehumidiFicaTion
T
imers
This screen allows adjustment for delay and min on time for dehumidification
mode.
Times are in place to prevent short cycling between dehumidification and
other control modes.
d
ehumidiFicaTion
h
ysTeresis
This screen displays hysteresis for enabling dehumidification during occupied and
unoccupied conditions.
%RH for indoor RH control and ºF for indoor dew point
control. Example: If indoor RH set point = 50%, dehumidification is enabled when
indoor RH equals 50% and above. Dehumidification is disabled when indoor RH
is below 44%.
Menu
c
old
c
oil
s
eT
p
oinT
This screen displays the temperature set pints for the cooling coil.
This screen
only appears if the unit is equipped with cooling. When in dehumidification mode,
the cooling ramp maintains the cold coil set point by increasing or decreasing
the amount of cooling provided from the cooling device installed. The calculated
coil set point has a min and max set point that is based on the demand from the
dehumidification ramp. When the demand is high, the temperature is low. If a
constant temperature off the coil is desired during dehumidification, the min and
max can be set to the same value. If a BMS is available, the set points can be
adjusted over the BMS.
d
ehumidiFicaTion
m
ode
- u
noccupied
.
If the unit is unoccupied while there is a dehumidification call, the unit will start
and dehumidify until the unoccupied dehumidification set points are satisfied.
The above dehumidification modes marked with an * indicate availability during
unoccupied mode. The unoccupied dehumidification mode can be set differently
than the occupied dehumidification mode. Reference Ctrl Variables/Advanced/
Unit Config/Unit Configuration Unoccupied Dehum Call for dehumidification
method options.
Control Variables
Dehumidification
The
Dehumidification
menu allows the user to view and adjust dehumidification
control parameters.
d
ehumidiFicaTion
m
ode
- o
ccupied
.
Possible Modes:
• Outside Air Temp is greater than cold coil set point plus offset (10ºF)
• Inside RH*
• Inside dew point*
• Outside dew point
• Inside RH or inside dew point*
• Inside RH or inside dew point or outside dew point
• Inside RH and inside dew point*
• Inside RH and inside dew point or outside dew point
*Available during unoccupied mode.
There must be a constant call for dehumidification for the duration of the enable
delay for dehumidification mode to become enabled. The call remains active until
conditions are satisfied and dehumidification mode has been active for the min
active time. Reference Ctrl Variables/Advanced/Unit Config/Unit Configuration
Occupied Dehum Call for dehumidification method options.